1. Field of the Invention
The present invention relates generally to a power supply, and more particularly to a power processing apparatus to supply light-emitting diode (LED) power and a method of releasing residual power.
2. Description of the Related Art
With advancement in technology, light-emitting diode (LED) is more and more popular in the modern market. LED has many advantages, including small size, short response time, long life, low decrement, strong surface, anti-vibration, emitting full-color light (including invisible light), low power loss, low radiant heat, and easy to manufacture. Therefore, more and more light sources use LED to replace light bubble or tube.
FIG. 1 shows a conventional power processing apparatus 70, including an input port 71, an output port 72, and a power transforming module 73. A power source 110 is connected to the input port 71 to provide AC power, and LEDs 80 are connected to the output port 72. The power transforming module 73 is between the input port 71 and the output port 72, including a capacitor unit 731, a rectifier-filter unit 732, and a DC/DC converter 733. The capacitor unit 731 and the LEDs 80 are in parallel connection. The rectifier-filter unit 732 is between the input port 71 and the DC/DC converter 733 to transform the AC power into more stable DC power. The DC/DC converter 733 receives the DC power from the rectifier-filter unit 732, and change to a predetermined voltage or current level DC power, and then the DC power is transmitted to the capacitor unit 731 and the LEDs 80 through the output port 72 to light the LEDs 80.
As shown in FIG. 2, the LEDs will keep lighting for a while after someone turns off the power switch SW because of the capacitor unit 731. Many consumers may think the electronic device is malfunctioned or has some problems. Therefore, the conventional power processing apparatus 70 still has to be improved.